Manufacture of steel.



UNITED STATES PATENT O ICE. v

JOHN w. SPENCER, or NEWBURN, ENGLAND.

MANUFACTURE OF STEEL.

Specification of Letters Patent. Original application filed July 31, 1903, Serial No.1167,782. Divided and .1...

PatentedAug-.- 1907. application filed October .29, 19.04.

Serial No. 230,578.

rendering such steel of greater utility for boiler plates,

ship plates, and all classes of iorging's such asaremade from so-called mild and medium hard steel. I

Thisapplication isa division otthe U. S. application Serial No. 167,782, filed July 31, 1903, covering'my method of manufacturingsteel. According to my invention I add to-all kinds of mild and medium hard steels containing carbon from .0592 up to .25 77; a larger proportion of silicon than has hith erto been used commercially. I

It is common knowledge that silicon has been and is used for such purposes as conferring solidity upon steel castings and ingots, and in much larger propor tions for the manufacture of the harder classes of steel, such as spring steel and tool steel.

It is the special object of my invention to utilize the valuable properties conferred upon mild and medium hard steels by the addition of proportions .of silicon varying from .7573 .up to 2%.; By this means the ten- .sile strength and elastic limit of the resulting steel are as to makea great difference in the cost of construction and carrying power of the-vessels For boiler plates and io'rgings the strength is. so much increased that an increased factor of safety may be obtained where it may not be considered expedient to reduce the weight;

My present invention consists, therefore, in utilizing this valuable property of silicon and applying it to ob- I tainsuch' results as are only at present attainable commercially by the use of nickel which is much more ere.

pensive to add than siliconand which is attended by certain disadvantages not possessed by the silicon.

One of the great advantages in theuse of silicon in such proportions as are hereinbefore specified, for increasing the strength'without loss oiducility, is, that plates and iorgin gsmay be obtained-practically free from surface defects, a well known difliculty in the use of nickel for such a purpose. The steel whichhas been improved by the addition of silicon is also'easily welded, which renders, it particularly suitable for plates.

' Hitherto the special addition of such largepropor present in use, and it is this which I particularly claim to have discovered.

In carrying out, my invention I proceed to 'melt a charge of suitable materials such as scrap and pig'iron either alone" or as a mixture in a crucible, open hearth,

' or other furnace, or Bessemer or other converter. Aiter the charge of pig-iron and scrap/Has been melted'and worked down or purified, as is usual in the Siemens or Bessemer processes, I then introduce the desired proportionotsilicon, or silicon alloy either into the furnace, or into the ladle, after which the mixture viscast into ingots or-other desired form.

In making my'improved steel in this manner man-. ganese maybe added in the'usual way cases it may be dispensed with.

Having now particularly described and ascertained the nature of my said invention, 'andin whatmanner the same is to be performed, I declare that what I claimis:- 4 As a 'new article of manufacture, a steel consisting of iron, .05 to .25 percent of carbon and .75 to 2 percent of silicon.- I i 4 .In testimony whereof I havehereunto set my hand in presence of two subscribing witnesses. I Y JOHN -W. SPENCER.

Wltne'sses: I

W. H. NIXON, D. Or'ro LILLY.

.75 or in certain 

